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Mobilization and Co‐Transport of Pyrene in the Presence of Pseudomonas aeruginosa UG2 Biosurfactants in Sandy Soil Columns
Author(s) -
Lafrance Pierre,
Lapointe Mireille
Publication year - 1998
Publication title -
groundwater monitoring and remediation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 47
eISSN - 1745-6592
pISSN - 1069-3629
DOI - 10.1111/j.1745-6592.1998.tb00173.x
Subject(s) - pyrene , soil water , environmental remediation , loam , chemistry , environmental chemistry , contamination , environmental science , biology , organic chemistry , soil science , ecology
Washing technologies are currently applied for the remediation of contaminated soils. The efficiency of biosurfactants produced by Pseudomonas aeruginosa strains to mobilize some hydrocarbons sorbed on soils has already been demonstrated. However, few studies have been made to define optimal procedures for the injection of these rhamnolipids in soil. This study examines (1) the efficiency of the biosurfactants produced by P. aeruginosa UG2 to mobilize pyrene from a contaminated sandy loam as compared to that of sodium dodecyl sulfate (SDS); (2) the injection procedures (surfactant concentration, pore water velocity, continuous or interrupted flow) that might affect the efficiency of pyrene mobilization using UG2 biosurfactants; and (3) the co‐transport of UG2 biosurfactants and pyrene. The UG2 biosurfactants were more efficient for pyrene mobilization than SDS and had much less impact on soil. The mobilization of pyrene was approximately proportional to the mass of UG2 biosurfactants injected for both the 0.25% and the 0.50% (w/v) concentrations used. Pyrene mobilization was not greatly dependent on either the pore water velocity—about 5.9 and 10.2 inch/h (15 and 26 cm/h)—or the duration of flow interruption (5 or 15 h), suggesting that mobilization was not rate limited under these conditions. The rhamnolipids appeared to be weakly retained in the soil. Based on the experimental results, it would be advantageous to use a high UG2 biosurfactant concentration, a high pore water velocity, and possibly a flow interruption of more than 15 h in order to reduce the injected volume and the duration of the treatment required. The 0.25% UG2 biosurfactant concentration greatly enhanced pyrene transport and could facilitate contaminant recovery.